Recent column leach testwork completed by Core Group for Red Metal Limited’s (ASX: RDM) Sybella Rare Earth Project has delivered strong rare earth extraction results from representative, coarsely crushed ore samples from the Kary Zone.
The results validate Red Metal’s proposed heap leach processing pathway and provide important metallurgical inputs as the company advances mine and metallurgical development studies towards pre-feasibility.
View the full ASX announcement here or read the summary below.
Key Results
Large Column Leach Tests (CLT) using weak sulphuric acid at ambient temperatures achieved strong rare earth extractions on representative composite samples from the Sybella Kary Zone.
The CLT were completed on -10mm and -20mm crushed samples of Saprock and Transitional mineralisation types, with results showing high rare earth extractions, low impurities in the pregnant leach solutions and low total-acid consumptions.
Standout results included:
- Neodymium extraction of 70–76%
- Praseodymium extraction of 71–78%
- Dysprosium extraction of 39–41%
- Terbium extraction of 43–44%
- Acid consumption of 23–27 kg H₂SO₄/t
The ASX announcement also notes that between 35% and 55% total rare earth extraction occurred within the first 30 days, highlighting scope for early cashflow once the heap is set up.
Core Resources’ Role
Core completed the column leach testwork on representative large area composite samples from the Kary Zone.
The program included CLT on coarsely crushed -10mm and -20mm material from the Saprock and Transitional mineralisation types, using weak sulphuric acid at ambient temperatures.
The testwork was designed to assess how each mineralisation type may perform during heap leaching and to support further optimisation of the project’s flowsheet and processing pathway.
The ASX announcement reports that the similarity in leach response between Saprock and Transitional ore types shows they can be readily co-processed in a bulk mining operation, reducing the need for strict grade control across these mineralisation domains.
Next Steps
The testwork outcomes will support Red Metal’s ongoing project development activities, including:
- Advancing mine and metallurgical development studies towards pre-feasibility
- Optimising mine and flowsheet design
- Preparing additional CLT on a larger -30mm size fraction
- Undertaking CLT using taller 6 metre columns
- Progressing ion exchange purification tests using pregnant CLT liquors
- Completing geotechnical testwork on leached ore from duplicated columns
Want to learn more about how Core supports rare earth and critical minerals projects like Sybella?
Visit our Metallurgical Testwork Services page or get in touch with our team to discuss how we can support your project.
